When I swapped the '96 drum brake Dana 60 rear out for a 2000+ Dana 60 disc brake rear a while back, I ran into an issue with my speed sensor. I believe later model sensor was different and had round pins inside it. The early model sensor had flat pins on the inside of it. The newer model sensor wouldn't connect to the existing pigtail on my '96 truck. To alleviate the issue, I purchased a new '96 style sensor and installed it in the newer disc brake rear. To-date, everything is working as it should.

Do you happen to know what year the rear is that you swapped into your truck?

 

Obviously the top of the sensor should not swivel, that's why there's a leak. The axle is from an older truck, pre-98. That's why a MY 2000 sensor doesn't fit the cover, but you can't use an older sensor as the connector is different. I guess somebody forced a newer sensor to fit.

 

The '00 sensor drops right into the '96 pig, er by drops in I mean has a nice fit as I'd expect an o-ring seal to feel.

I think there's a leak because -- and this is something I neglected to mention earlier -- there's a tiny hole in the bottom of the present sensor. It's not exactly a pinhole, more like an offset oval hole and it's small and almost looks factory. This is one reason I inspected a new sensor at my local O'Reilly, and I found no hole in the bottom of the sensor. However, I also thought it unlikely a quart of gear oil had made its way thru said hole AND/OR around the o-ring..

Now that I've seen the leak I am more confident in my diagnosis of a leaky sensor (shrug)

I covered the differences in connectors complete with pics in Post #2 here:
https://dodgeforum.com/forum/2nd-gen...fferences.html

 

Gotta consider the velocity that fluid has when it's flung off the ring gear when you are doing 55 mph...... that is a LOT of force. Even a TINY hole would pass a significant amount of fluid.....

 

I agree, the ring gear flings it up (I've enjoyed Banks' vids with custom clear diff covers in the past) and add in temperature variations inside the axle vs ambient winter air and I wonder if you might see a sort of venturi/siphon effect....ie once it gets "pumping" it might almost self-perpetuate so long as the ring gear keeps supplying oil.

Still, I didn't believe it until I confirmed the source of the leak. I wasn't willing to drop in a $40 sensor on a maybe. I can be an excellent operator of the parts cannon, but I usually regret the results

 

You're missing the point. The sensor fits into the housing just fine but interferes with the old style little cover. Pretty obvious if you look at them. On the one you have somebody has forcefully spun the top part around to make it fit.

 

Leave the little cover off. It's on TOP of the pig, not on the bottom.... I would like to think it's pretty safe up there. Besides, anything that come up there that would be interested in damaging the sensor, would trash the wires in any event.

 

Ok yanked the sensor tonight:

This sensor appears OEM - scribe indicates Chrysler symbol

Rotational stop clockwise - scribe indicates

Rotational stop CCW - scribe indicates

Started prying it apart and this green o-ring appeareth. There's little reason to cram an o-ring into a sensor unless you wanted it to spin. It could just be epoxied or otherwise sealed.

When assembled the entire magnet and windings spin with the connector in the lower housing

I completely understand the sensor doesn't NEED to rotate and I'm not worried about a fixed-position aftermarket. I'm merely demonstrating at least some OEMs were built to rotate roughly 90 degrees as needed

 

Aftermarket is built such that head is captive and canNOT rotate. Scribes indicate stops

 

A welding table, F-clamp and all-sixteenths fixes all.

I completely understand the shield is not necessary - I just have FUN with tools and mechanical. If you enjoy your job you'll never work a day in your life, as they say